Multifunctional Optical

Nonlinear optical phenyldiazo chromophores, (II), and (IE), were prepared by Gharavi [4] and Lindsey [5], respectively, and used as multifunctional optical switches. 

Konorov SO, Zheltikov AM, Scalora M (2005a) Photonic crystal fiber as a multifunctional optical sensor and sample collector. Opt Express 13 3454—3459... 

We exclusively consider optical techniques of detection here since that is where the authors expertise such as it is resides. In this section, we want to reveal a few of the tricks that we have found helpful in building a high-speed multifunction optical detection apparatus. 

Multifunctional materials will play an important role in the development of Photonics Technology. This paper describes novel multifunctional polymeric composites for applications in both active and passive photonic components. On the molecular level, we have introduced multifunctionality by design and synthesis of chromophores which by themselves exhibit more than one functionality. At the bulk level, we have introduced the concept of a multiphasic nanostructured composites where phase separation is controlled in the nanometer range to produce optically transparent bulk in which each domain produces a specific photonic function. Results are presented from the studies of up-converted two-photon lasing, two-photon confocal microscopy, optical power limiting, photorefractivity and optical channel waveguides to illustrate the application of the multifunctional optical composites. 

P. Frach, H. Bartzsch, K. Taeschner, J. Liebig, F. Schultheiss, Multifunctional optical coatings on polymers deposited by pulse magnetron sputtering and magnetron enhanced... 

This aspect is not included here, but is related to optical flow diagnostics. It is based again on the principle of the optical Doppler effect. Multifunctional equipment is available for noncontact measurements of flow-induced vibration on surfaces of structural elements, for acoustic measurements, and for calibration of accelerometers and vibration transducers. 

Shibasald et al. reported that lithium-containing, multifunctional, heterobimetallic catalysts such as LaLi3tris((l )-6,6 -dibromobinaphthoxide) 35, with moderate Lewis acidity in non-polar solvents, promote the asymmetric Diels-Alder reaction to give cycloadducts in high optical purity (86% ee) [53] (Scheme 1.67). The lithium... 

Gautier S.M., Blum L.J., Coulet P.R., Multifunction fiber-optic sensor for the bioluminescent flow determination of ATP or NADH, Anal. Chim. Acta 1990 235 243. 

MNFs, optical cylinders, disks, and microspheres can be assembled in more complex multifunctional sensing structures. One of the suggested structures is... 

Yazdanfar, S., Chen, Y. Y, So, P T. C., and Laiho, L. H. 2007. Multifunctional imaging of endogenous contrast by simultaneous nonlinear and optical coherence microscopy of thick tissues. Micr. Res. Tech. 70 628-633. 

Biomaterials such as proteins/enzymes or DNA display highly selective catalytic and recognition properties. Au nanoparticles or nanorods show electronic, photonic and catalytic properties. The convergence of both types of materials gives rise to Au NP-biomolecule hybrids that represent a very active research area. The combination of properties leads to the appearance of biosensors due to the optical or electrical transduction of biological phenomena. Moreover, multifunctional Au NP-peptide hybrids can be used for targeting nuclear cells where genetic information is stored and could be useful for biomedical applications [146]. 

Because the cast films are relatively thin, the optical density of the light absorbing species can he low and can vary with time of exposure. Additionally, the depth penetration of the absorbed light can be inhomogeneous in some systems. However, thin films can be mounted directly in UV/visible or infrared spectrometers, and so the course of the photopolymerization (and the rate) can be monitored directly in some systems. The most common observation made is the disappearance of monomer (e.g., loss of double bond absorption in the IR) as a function of irradiation time. It must be emphasized that in most thin film compositions important industrially, the monomers used are multifunctional. The polymer which results is then highly cross-linked and simple kinetic arguments are usually not valid. 

As an example, both monofunctional and multifunctional polymeric mercapto-esters were deposited onto optically smooth silicon wafers coated with vapor-deposited copper. The copper had been oxidized to Cu20, as verified by XPS. Infrared reflectance (RAIRS) at 81° (4 cm-1 resolution, 2000 scans) using an MCT detector yielded information on both the nature and the durability of the mercaptoester bond to the metal oxide film. A 16 cm l shift (1740— 1724 cm-1) was observed in the carbonyl absorption of stearyl thioglycolate (STG) deposited onto the Cu20 mirror. The absorption spectrum of the carbonyl region is illustrated in Fig. 11, both for the pure STG and the reacted monolayer. 

The asymmetric catalytic nitroaldol reaction, also known as the asymmetric Henry reaction, is another example of an aldol-related synthesis of high general interest. In this reaction nitromethane (or a related nitroalkane) reacts in the presence of a chiral catalyst with an aldehyde, forming optically active / -nitro alcohols [122], The / -nitro alcohols are valuable intermediates in the synthesis of a broad variety of chiral building blocks, e.g. / -amino alcohols. A highly efficient asymmetric catalytic nitroaldol reaction has been developed by the Shibasaki group, who used multifunctional lanthanoid-based complexes as chiral catalysts [122-125],... 

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